Field of the Invention
The present invention relates to an image processing device configured to process so-called pupil-divided images and a control method thereof, and a program for causing a computer to perform the control method.
Description of the Related Art
Conventionally, a method of enlarging the dynamic range of an image sensor using pupil-divided images has been proposed. For example, Japanese Patent Application Laid-Open No. 2002-199284, described below, discloses a technique of enlarging the dynamic range of a sensor by changing the accumulation time or readout gain by different pupil-divided images to thereby obtain a plurality of images of different exposures, and synthesizing those images.
Further, it has been known conventionally that pupil intensity distribution differs from one pupil-divided image to another. Examples of such technique are disclosed in Japanese Patent Application Laid-Open No. 2013-125095, and Japanese Patent Application Laid-Open No. 2009-258868, described below, for example.
However, in the dynamic range enlargement addition mode disclosed in Japanese Patent Application Laid-Open No. 2002-199284 described above, an influence of shading due to vignetting of a pupil reduces a dynamic range enlargement effect.